Unit dose dispensing mechanisms

ABSTRACT

Mechanisms for dispensing items such as medications and medical supplies. Different mechanisms may be tailored to dispensing different kinds of items, for example medications in single dose packages, vials, syringes, or other similarly-shaped items. The dispensers may be placed in a dispensing unit that includes a lockable restock drawer and a dispense drawer into which items are dispensed by the dispensing mechanisms. The various kinds of dispensing mechanisms may be installed in the restock drawer in any workable proportion and arrangement. The dispensing mechanisms include multiple sensing technologies for tracking and inventory of items and for accurate sensing of items as they are dispensed.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a division of U.S. patent application Ser. No.15/693,276, filed Aug. 31, 2017 and titled “Unit Dose DispensingMechanisms”, the entire disclosure of which is hereby incorporated byreference herein for all purposes.

BACKGROUND OF THE INVENTION

Many industries rely on the accurate inventory and dispensing of secureitems. For example, in a hospital setting, it is of paramount importancethat patients be given the correct medications in the correct doses. Inaddition, it is legally required that controlled substances be securedand accurately tracked, and it is also important that inventories ofmedications and supplies be tracked so that proper business controls canbe implemented.

Various dispensing cabinets and carts have been developed to assist inthe management of medications and other items. However, improvements arestill desired in the reliability of dispensing and tracking of items,and it is also desirable to reduce the amount of space required for itemstorage and dispensing.

BRIEF SUMMARY OF THE INVENTION

According to one aspect, a dispensing mechanism comprises a connectorfor receiving electrical signals from a cabinet in which the dispensingmechanism is installed, an actuator that operates in response to theelectrical signals, a non-circular sprocket driven by the actuator, anda belt driven by the sprocket. The belt comprises a plurality of links,and is configured to circulate within a chamber when driven by theactuator. The dispensing mechanism further comprises a plurality ofpaddles integrally formed with the links of the belt for receivingbetween pairs of the paddles items to be dispensed, the paddlesextending from the belt. The dispensing mechanism also includes ahousing defining the chamber and defining an opening at the bottom ofthe chamber, such that a single item drops from between its respectivepaddles and through the opening when the segmented belt is incrementallyadvanced and the paddle supporting the item approaches a verticalorientation due to the advancement of the belt.

According to another aspect, a dispensing mechanism comprises a set ofvertical channels of a shape and size to receive a number of vials andhold the vials in vertical stacks. The dispensing mechanism alsoincludes a connector for receiving electrical signals from a cabinet inwhich the dispensing mechanism is installed, an actuator that moves inresponse to the electrical signals, and a plurality of rotatablereceivers driven by the actuator. Each of the rotatable receivers ispositioned under a respective one of the vertical channels and definesan open-sided cavity of a shape and size to receive a vial. Thedispensing mechanism also includes a housing defining opening at thebottom of the dispensing mechanism. When the rotatable receivers arerotated, their respective cavities sequentially align with the verticalchannels, such that upon alignment, one of the vials drops into therespective cavity through the open side of the cavity, and when one ofthe cavities holding a vial approaches a downward vertical orientation,a single vial drops from the open side of the downwardly-oriented cavityand through the opening.

According to another aspect, a dispensing mechanism comprises aconnector for receiving electrical signals from a cabinet in which thedispensing mechanism is installed, an actuator that moves in response tothe electrical signals, and a housing for storing items to be dispensed.The housing comprises a floor having an opening through which items areto be dispensed, and the housing includes means for feeding items bygravity toward the opening in the floor. The dispensing mechanismfurther comprises a moveable slide driven by the actuator, the moveableslide having a slot through the movable slide, into which slot items tobe dispensed fall one at a time, and a spring that biases the slide intoa default position in which the slot of the moveable slide is notaligned with the opening in the floor. When the slide is moved by theactuator, the slide translates against the action of the spring into aposition in which the slot in the slide aligns with the opening in thefloor, allowing a single item in the slot to fall through the opening tobe dispensed.

According to another aspect, a system for detecting items comprises oneor more light emitters directed across an opening, and one or more lightreceivers. Each of the light receivers generates a signal indicating theintensity of light received by the respective light receiver. The systemfurther comprises a dispensing mechanism that contains one or more itemsto be dispensed, and is configured to cause the items to be dispensedone at a time through the opening. The system also comprises circuitrythat compares the outputs of the one or more light receivers withrespective reference signals and generates a detection signal based onthe result of the comparisons. The detection signal indicates one ormore conditions selected from the set of conditions consisting of a) anyone or any number of the one or more light receivers is producing anoutput signal that is below one of the reference signals, and b) any oneor any number of the one or more light receivers is producing an outputsignal that is above one of the reference signals. The system alsoincludes a controller that receives the detection signal. The controlleris configured to command the dispensing of an item, monitor the outputof the circuitry for a detection signal produced in conjunction with thedispensing of the item, and during a time when no dispensing isrequired, monitor the output of the circuitry for a detection signalthat is not produced in conjunction with the dispensing of any item.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an example cabinet in which the invention may beembodied.

FIG. 2 illustrates a dispensing unit in accordance with embodiments ofthe invention.

FIG. 3 is a detail view of a portion of FIG. 2.

FIG. 4A illustrates the dispensing unit of FIG. 2 fully loaded withdispensing mechanisms.

FIG. 4B illustrates the dispensing unit of FIG. 2 fully loaded with adifferent mix of dispensing mechanisms.

FIG. 5 is a reverse angle view of a portion of the fully-loadeddispensing unit of FIG. 4A.

FIGS. 6A and 6B illustrate upper and lower views of a first dispensingmechanism in accordance with embodiments of the invention.

FIGS. 7A and 7B illustrate partially exploded views of the dispensingmechanism of FIGS. 6A and 6B.

FIG. 8 shows a partially cutaway oblique view of the dispensingmechanism of FIGS. 6A and 6B.

FIG. 9 illustrates a typical blister pack as may be dispensed by thedispensing mechanism of FIGS. 6A and 6B.

FIG. 10 shows an orthogonal view of a cassette portion of the dispensingmechanism of FIGS. 6A and 6B, with a back cover removed to show someinternal workings of the cassette.

FIG. 11 is an oblique detail view of the upper portion of the cassetteof FIG. 10, providing more detail about the construction of thecassette.

FIGS. 12A and 12B illustrate upper and lower partially exploded obliqueviews of a second dispensing mechanism in accordance with embodiments ofthe invention.

FIG. 13 illustrates a vial as may be dispensed by the dispensingmechanism of FIGS. 12A and 12B.

FIG. 14 is a cutaway oblique view of a cassette portion of thedispensing mechanism of FIGS. 12A and 12B, partially filled with vials.

FIG. 15 illustrates a lower oblique view of the cassette portion of FIG.14.

FIG. 16 illustrates a partially-cutaway rear view of the lower portionof a dispenser portion of the dispensing mechanism of FIGS. 12A and 12B.

FIG. 17 illustrates a front view of the lower portion of the dispenserof FIG. 16, showing additional details of its operation.

FIGS. 18A and 18B illustrate upper and lower views of a third dispensingmechanism in accordance with embodiments of the invention.

FIG. 19 shows an oblique view of a dispenser portion of the dispensingmechanism of FIGS. 18A and 18B with some parts removed, revealinginternal details of the operation of the dispenser portion.

FIG. 20 illustrates a syringe as may be dispensed by the dispensingmechanism of FIGS. 18A and 18B.

FIGS. 21A and 21B illustrate a cassette portion of the dispensingmechanism of FIGS. 18A and 18B with certain outer panels removed, andrevealing internal details of the cassette portion.

FIGS. 22A-22C illustrate a cutaway view of portions of the dispensingmechanism of FIGS. 18A and 18B and their operation to dispense asyringe.

FIG. 23 illustrates an electrical block diagram of the dispensing unitof FIG. 2, in accordance with embodiments of the invention.

FIG. 24 illustrates an electrical block diagram of a printed circuitboard in the restock drawer of FIG. 2, in accordance with embodiments ofthe invention.

FIG. 25 illustrates an electrical block diagram of a dispenser as may beused in the dispensing mechanisms of FIGS. 6A, 12A, and 18A, inaccordance with embodiments of the invention.

FIGS. 26A and 26B illustrate upper and lower views of a dispensingmechanism in accordance with other embodiments of the invention.

FIGS. 27A and 27B illustrate partially exploded views of the dispensingmechanism of FIGS. 26A and 26B.

FIG. 28 shows a partially cutaway oblique view of the dispensingmechanism of FIGS. 26A and 26B.

FIG. 29 shows an orthogonal view of a cassette portion of the dispensingmechanism of FIGS. 26A and 26B, with a back cover removed to show someinternal workings of the cassette.

FIG. 30 shows a partially exploded view of the cassette of FIG. 29.

FIG. 31 illustrates the spacing between parts of the cassette of FIG.29.

FIG. 32 shows a rear oblique view of the cassette of FIG. 29.

FIG. 33 shows a magnified view of part of FIG. 32.

FIG. 34 illustrates the locations of several openings in the cassette ofFIG. 29, in accordance with embodiments of the invention.

FIG. 35 illustrates a number of ties installed in the openings shown inFIG. 34.

FIGS. 36A and 36B illustrate upper and lower partially exploded obliqueviews of a dispensing mechanism, in accordance with other embodiments ofthe invention.

FIG. 37 is a cutaway oblique view of example a cassette partially filledwith vials, in accordance with embodiments of the invention.

FIG. 38 illustrates a lower oblique rear view of the cassette of FIG.37.

FIG. 39A illustrates a partially-cutaway rear view of a dispenser inaccordance with embodiments of the invention, and FIG. 39B illustratesan oblique front view of the dispenser.

FIG. 40 shows a rear orthogonal view of a lower portion of cassette inaccordance with embodiments of the invention, showing the operation of abrake.

FIG. 41 illustrates the locations of several openings in the cassette ofFIG. 37, in accordance with embodiments of the invention.

FIGS. 42 and 43 illustrate a number of ties installed in the openingsshown in FIG. 41.

FIGS. 44A and 44B illustrate upper and lower views of a dispensingmechanism in accordance with other embodiments of the invention.

FIG. 45 shows an oblique view of a dispenser in accordance withembodiments of the invention with some parts removed, revealing internaldetails of the operation of the dispenser.

FIG. 46 illustrates a cutaway oblique view of a cassette in accordancewith embodiments of the invention.

FIGS. 47A-47C show orthogonal section views of the lower part of thecassette of FIG. 46.

FIG. 48 shows a cutaway oblique view of a portion of the cassette ofFIG. 47, and illustrates the operation of a brake.

FIGS. 49A and 49B show the locations of several openings in the cassetteof FIG. 47, in accordance with embodiments of the invention.

FIGS. 50 and 51 show several ties inserted into the openings shown inFIGS. 49A and 49B.

FIG. 52 schematically illustrates an arrangement of a light curtain inaccordance with embodiments of the invention.

FIG. 53 shows the light curtain of FIG. 52 with the light beinginterrupted by a dispensed item.

FIG. 54 schematically illustrates an arrangement of a light curtain inaccordance with other embodiments of the invention.

FIG. 55 shows the light curtain of FIG. 54 with the light beingreflected by a dispensed item.

FIG. 56 schematically illustrates an arrangement of a light curtain inaccordance with other embodiments of the invention.

FIG. 57 shows the light curtain of FIG. 56 with the light beinginterrupted by a dispensed item.

FIG. 58 shows light emitter circuitry in accordance with embodiments ofthe invention.

FIG. 59 shows light detection circuitry in accordance with embodimentsof the invention.

FIG. 60 shows light detection logic circuitry in accordance withembodiments of the invention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 illustrates an example cabinet 100 in which the invention may beembodied. Cabinet 100 includes various doors 101 and drawers 102providing access to compartments for storing items such as medicalsupplies or medications. For example, supplies such as bandages, swabs,and the like may be stored in unlocked compartments such as may beaccessed through one of doors 101. Medications may be stored inindividually lockable compartments within drawers such as drawers 102. Acomputer 103 maintains records of the contents of cabinet 100, and maycontrol access to individual compartments. For example, a floor nurseneeding to obtain a dose of medication for a hospital patient may enterhis or her identification and the medication required into computer 103.Computer 103 verifies that the nurse is authorized to remove themedication, and unlocks a particular drawer 102 and a particularcompartment within the drawer containing the required medication.Computer 103 may also control lights that guide the nurse to the correctdrawer and compartment, to help ensure that the correct medication isdispensed. In addition, computer 103 may communicate with a centralcomputer system that coordinates information from many storage anddispensing devices such as cabinet 100.

While embodiments of the invention are described in the context ofstationary cabinet 100, it will be recognized that the invention may beembodied in other kinds of storage devices, for example movablecabinets, carts, storage rooms, and the like. Example dispensing devicesare described in the following commonly owned U.S. patents and patentapplications, the contents of which are hereby incorporated byreference: U.S. Pat. No. 6,272,394, issued on Aug. 7, 2001 to Lipps,U.S. Pat. No. 6,385,505, issued on May 7, 2002 to Lipps, U.S. Pat. No.6,760,643, issued on Jul. 6, 2004 to Lipps, U.S. Pat. No. 5,805,455,issued on Sep. 8, 1998 to Lipps, U.S. Pat. No. 6,609,047, issued on Aug.19, 2003 to Lipps, U.S. Pat. No. 5,805,456, issued on Sep. 8, 1998 toHigham et al, U.S. Pat. No. 5,745,366, issued on Apr. 28, 1998 to Highamet al., an U.S. Pat. No. 5,905,653, issued on May 18, 1999 to Higham etal., U.S. Pat. No. 5,927,540, issued on Jul. 27, 1999 to Godlewski, U.S.Pat. No. 6,039,467, issued on Mar. 21, 2000 to Holmes, U.S. Pat. No.6,640,159, issued on Oct. 28, 2003 to Holmes et al., U.S. Pat. No.6,151,536, issued on Nov. 21, 2000 to Arnold et al., U.S. Pat. No.5,377,864, issued on Jan. 3, 1995 to Blechl et al., U.S. Pat. No.5,190,185, issued on Mar. 2, 1993 to Blechl, U.S. Pat. No. 6,975,922,issued on Dec. 13, 2005 to Duncan et al., U.S. Pat. No. 7,571,024,issued on Aug. 4, 2009 to Duncan et al., U.S. Pat. No. 7,835,819, issuedon Nov. 16, 2010 to Duncan et al., U.S. Pat. No. 6,011,999, issued onJan. 4, 2000 to Holmes, U.S. Pat. No. 7,348,884, issued on Mar. 25, 2008to Higham, U.S. Pat. No. 7,675,421, issued on Mar. 9, 2010 to Higham,U.S. Pat. No. 6,170,929, issued on Jan. 9, 2001 to Wilson et al., U.S.Pat. No. 8,155,786 to Vahlberg et al., issued on Apr. 10, 2012, U.S.Pat. No. 8,073,563 to Vahlberg et al., issued on Dec. 6, 2011, U.S.Patent Application Publication No. 2008/0319577 of Vahlberg et al.,published on Dec. 25, 2008, U.S. Pat. No. 8,140,186 to Vahlberg et al.,issued on Mar. 20, 2012, U.S. Pat. No. 8,126,590 to Vahlberg et al.,issued on Feb. 28, 2012, U.S. Pat. No. 8,027,749 to Vahlberg et al.,issued on Sep. 27, 2011, U.S. Patent Application Publication No.2008/0319790 of Vahlberg et al., published on Dec. 25, 2008, U.S. PatentApplication Publication No. 2008/0319789 of Vahlberg et al., publishedon Dec. 25, 2008, U.S. Pat. No. 8,131,397 to Vahlberg et al., issued onMar. 6, 2012, U.S. Patent Application Publication No. 2008/0319579 ofVahlberg et al., published on Dec. 25, 2008, and U.S. Patent ApplicationPublication No. 2010/0042437 of Levy et al., published on Feb. 18, 2010.Embodiments of the present invention may incorporate features from thedevices described in these documents, in any workable combination.

In the above scenario, the nurse may be given access to a compartmenthaving a large number of doses of the medication, and he or she maysimply remove the number immediately required.

Cabinet 100 also includes a return bin 104, into which unused items canbe placed, for later return to stock by a pharmacy technician.

When further control and tracking accuracy is required, medications maybe placed in a dispensing unit such as dispensing unit 105. Dispensingunit 105 includes a restock drawer 106 and a dispense drawer 107.Restock drawer includes in turn a number of dispensing mechanisms (notvisible in FIG. 1) that, under control of computer 103, can dispensesingle items into dispense drawer 107. Dispense drawer 107 can then beopened to retrieve the dispensed items. Restock drawer 106 is accessibleonly by specially-authorized persons, for example for restocking by apharmacy technician.

FIG. 2 illustrates dispensing unit 105 in more detail, including restockdrawer 106 and dispense drawer 107. A number of dispensing mechanismsmay be installed within restock drawer by 106 attaching them to rails201. Only a few dispensing mechanisms 202, 203, 204 are shown in FIG. 2.Different types of dispensing mechanisms may be present, depending onthe kinds of items to be dispensed, as is discussed in more detailbelow. The different kinds of dispensers may be of differing sizes, andrails 201 may be configured as necessary to accommodate a particular mixof dispensing mechanisms, by fixing rails 201 to different sets ofhangers 205.

For example, dispensing mechanism 203 is a double width mechanism,placed between rails that are two bays wide, while dispensing mechanisms202 and 204 are single width mechanisms, placed between rails 201 thatare connected to adjacent sets of hangers 205. Other sizes ofdispensers, for example triple and quadruple widths are also possible.

FIG. 2 also illustrates that dispense drawer 107 and restock drawer 106form a nested pair of drawers. That is, restock drawer 106 can slide outof cabinet 100 on guides 206 for restocking, maintenance, and the like,carrying dispense drawer 107 with restock drawer 106. Similarly,dispense drawer 107 can slide in and out of restock drawer 106 onsimilar guides not easily visible in FIG. 2.

In some embodiments, dispense drawer 107 may conveniently serve as awork surface for the user of cabinet 100 or a similar device. Forexample, once an item has been dispensed into dispense drawer 107 andthe user has opened dispense drawer 107 to retrieve the item, the usermay use the flat bottom of dispense drawer 107 to rest a note pad,computer, or other item he or she may use to document or make notesabout the transaction. Dispensing unit 105 may include features tofacilitate the use of dispense drawer 107 as a work surface. Forexample, the guides or other slide mechanism by which dispense draweropens may include a detent at the openmost position of dispense drawer107, to lend stability to dispense drawer 107 while it is used as a worksurface.

FIG. 3 is a detail view of a portion of FIG. 2, showing that at eachhanger 205 is an electrical connector 301. Each connector 301 connectswith a mating connector attached to wiring within a rail 201 positionedat the respective hanger 205, supplying power and signals coming fromother systems within cabinet 100. Other connectors 302 are spaced alongthe rails, for making electrical connections with the dispensingmechanisms such as dispensing mechanisms 202, 203, and 204. Toaccomplish the required electrical connections, each rail 201 may housea wiring harness, a printed circuit board assembly (PCBA), or the like.Thus, computer 103 can communicate individually with any dispensingmechanism within restock drawer 106. Cabling from all of the connectorsconverges at a circuit board (not visible) at the back of dispensingunit 105, which in turn connects to other electronics within cabinet 100via one or more flexible cables (not visible in FIG. 3), which permitsdispensing unit 105 to slide out of cabinet 100 for restocking,maintenance, and the like.

FIG. 4A illustrates dispensing unit 105 fully loaded with sevendispensing mechanisms 202, 14 dispensing mechanisms 203, and sevendispensing mechanisms 204, fully populating the available spaces onrails 201. It will be recognized that this arrangement of dispensingunits is but one example of many, many arrangements of dispensing unitsthat could be employed. For example, restock drawer 106 may not be fullypopulated with dispensing units. Only one or two different kinds ofdispensing mechanisms may be present, or four or more kinds ofdispensing units may be present. Different kinds of dispensing units maybe present in any workable proportions, and like dispensing units neednot be installed next to each other. Example dispensing unit 105 canhold up to 42 single width dispensing mechanisms (with two additionalrails 201 installed). One example of this is shown in FIG. 4B, in whichdispensing unit is loaded with 42 dispensing mechanisms 202.

Preferably, each dispensing unit can identify itself through itsrespective connector 302, and computer 103 can create a map of theparticular arrangement of dispensing units that are installed. Computer103 can also preferably detect the presence of a dispensing unit at anyone of the bay positions, through the respective connector 302 or via aseparate sensor. In addition, each dispensing unit can preferably alsocommunicate to computer 103 the kind and quantity of items it containsand stands ready to dispense.

FIG. 5 is a reverse angle view of a portion of the fully-loadeddispensing unit 105 of FIG. 4A, showing a back panel 501 of restockdrawer 106. Preferably, both restock drawer 106 and dispense drawer 107include latching mechanisms operable by computer 103, to prevent theopening of the drawers at improper times. For example, computer 103 maypermit restock drawer 106 to be opened only when computer 103 hasreceived a proper security code from a restocking technician, and maypermit dispense drawer 107 to be opened only after an item has beendispensed from one of dispensing mechanisms 202, 203, 204. A latchingmechanism 502 for locking and unlocking restock drawer 106 is visible inFIG. 5. A similar latching mechanism may be provided inside restockdrawer 106 for locking and unlocking dispense drawer 107. Also visiblein FIG. 5 are various connectors 503 for connecting to other electronicswithin cabinet 100, for example a power supply, computer 103, or otherelectronic components through one or more flexible cables (not shown).

Dispensing Mechanisms

The dispensing mechanisms 202, 203, 204 may be tailored to the size andtype of items to be dispensed, and provide improvements over priordispensing mechanisms. For example, one prior type of dispensingmechanism used a helical coil, and items to be dispensed were positionedbetween the coils of the helix. The coil was rotated until an item wasadvanced beyond the grasp of the coil and was dispensed. This kind ofdispenser, although widely and successfully used, is somewhat limited inthe shapes and sizes of items that could be dispensed, as the items mustbe compatible with the pitch and size of the coil.

Dispensing Mechanism for Blister Packs and Other Small Items

FIGS. 6A and 6B illustrate upper and lower views of dispensing mechanism202 in more detail. Dispensing mechanism 202 may be especially usefulfor dispensing small items such as individual medicine doses packaged inwell-known “blister packs”, although dispensing mechanism 202 may beuseful for dispensing may other kinds of items as well.

As is visible in FIG. 6A, a button 601 at the top of dispensingmechanism 202 allows a user authorized to access the interior of restockdrawer 106 to signal computer 103, for example to record the fact thatdispensing mechanism 202 has been refilled. A light 602 enables computer103 to communicate to the user, for example flashing the light to directthe user to restock this particular dispensing mechanism.

As is visible in FIG. 6B, a connector 603, compatible with connectors302 on rails 201, is positioned to engage one of connectors 302 whendispensing mechanism 202 is installed in restock drawer 106. Variousparts of dispensing mechanism 202 collectively constitute a housing thatdefines an opening 604 at the bottom of dispensing mechanism 202,through which items are dispensed. Dispensing mechanism 202 may beremovably secured to one of rails 201 using a snap mechanism, one ormore screws, or by another method.

As is shown in FIGS. 7A and 7B, example dispensing mechanism 202comprises a dispenser 701 and a cassette 702, which are separable. Forexample, dispenser 701 and cassette 702 may snap together, may beseparable with the removal of one or a small number of screws, or may bereasonably separable in some other way without damage to eitherdispenser 701 or cassette 702. In this way, restocking may beaccomplished by replacing a depleted cassette 702 with a full cassette702. A gear 703 engages a driving gear (not easily visible in FIG. 7A)within dispenser 701 when cassette 702 is assembled to dispenser 701.

Preferably, as will be discussed in more detail below, cassette 702 doesnot contain any active electrical components. All of the activecomponents of example dispensing mechanism 202 reside in dispenser 701.For example, an antenna 704 can excite a passive memory chip 705 incassette 702, to determine the contents of cassette 702 (written intopassive memory chip 705 when cassette 702 was filled at a remotelocation). If desired, antenna 704 can also be used to update the datain passive memory chip 705. This wireless data exchange may use anysuitable wireless protocol, for example Near Field Communications (NFC),radio frequency identification (RFID), or another wireless protocol.

Dispenser 701 can preferably automatically detect the installation andremoval of cassette 702. This automatic detection may facilitate theinventory and tracking of items, and also can help prevent illicitdiversion of items. The detection may be accomplished in any suitableway, for example periodic polling using antenna 704, a contact sensor(not shown) that can detect the presence of cassette 702electromechanically, or by another technique.

In other embodiments, a dispensing mechanism in accordance withembodiments of the invention may not have the separable architecture ofdispensing mechanism 202, but may be a single unit including space forstoring items to be dispense and including an actuator and othercomponents for dispensing items. In other embodiments that do include acassette, the cassette may include active components, for example amotor or other actuator, light emitters for sensing, or othercomponents.

As are visible in FIG. 7A, a light emitter 706 and two light receivers707 are positioned near the bottom of dispenser 701. In operation, lightfrom light emitter 706 reflects from reflective surface 708 (visible inFIG. 7B) and returns to light receivers 707, so long as it is notinterrupted by an item being dispensed and falling through the “lightcurtain” formed across opening. When an item is dispensed throughopening 604, it interrupts the light received by either or both of lightreceivers 707, and dispenser 701 can note that an item has in fact beendispensed. If no light interruption is detected despite a command todispense an item, computer 103 may assume that a misfeed or otherproblem has occurred, or that cassette 702 is empty. By using moresophisticated monitoring strategies, accidental dispensing of multipleitems may be detected. For example, if two interruptions of the lightcurtain are detected closely spaced in time, a double feed may beindicated. Emitter 706 may be of any suitable type of emitter, and mayemit light in any suitable wavelength or combinations of wavelengths.For example, light emitter 706 may be a light emitting diode, a lasersuch as a vertical cavity semiconductor emitting laser (VCSEL) oranother kind of light source, and may emit visible light, infraredlight, or light in other suitable wavelength bands or combinations ofwavelength bands.

In other embodiments, light emitter 706 and receivers 707 may be onopposite sides of opening 604, so that receivers 707 receive lightdirectly from light emitter 706 until the light is interrupted by thedispensing of an item.

FIG. 8 shows a partially cutaway oblique view of dispensing mechanism202, revealing some internal details of dispenser 701. A motor 801having a right-angle drive turns driving gear 802, which engages gear703 on cassette 702 to actuate cassette 702. Motor 801 may be, forexample, a stepper motor whose angular position can be readily movedincrementally and held. In that case, an item may be dispensed byadvancing motor 801 by a number of steps known to correspond to onedispensing operation. If the light curtain does not detect that an itemis dispensed, motor 801 may be advanced further, and if no dispensing isyet detected, an error message may be generated, or it may be assumedthat cassette 702 is empty. Alternatively, motor 801 may be a simple DCor AC motor, in which case dispensing may be accomplished by simplyrunning motor 801 until the dispensing of an item is detected, and thenshutting off the motor so that motor 801 is advanced incrementally asfar as is needed. A time limit may be imposed, such that if nodispensing is detected within the time limit with motor 801 running, themotor may be shut off and an error message generated.

In other embodiments, an actuator other than a motor may be used. Forexample, a solenoid or memory metal actuator may provide a reciprocatingmotion that is used to drive the driving gear within dispenser 701 usinga ratchet or ratchet-like arrangement. Other kinds of actuators anddriving arrangements are possible.

A microprocessor, microcontroller, or similar controlling circuitry mayreside within dispenser 701, and may operate the various activecomponents and sensors of dispenser 701 in response to high-levelcommands from a supervisory controller elsewhere within restock drawer106, or from computer 103. In that case, dispenser 701 is considered a“smart” dispenser, because it includes some processing intelligence.However, other architectures are possible. For example, logic signalsfrom a supervisory controller elsewhere within restock drawer 106 mayoperate dispenser 701.

As was discussed above, dispensing mechanism 202 may be especiallyuseful for dispensing individual medicine doses such as those commonlypackaged in blister packs. FIG. 9 illustrates a typical blister pack901. A flat portion 902 may be made of cardboard, a stiff plastic, orthe like. A plastic bubble-like “blister” 903 is laminated to flatportion 902, with a capsule or the like (not visible) confined withinblister 903.

FIG. 10 shows an orthogonal view of cassette 702, with its back coverremoved, and showing the internal workings of the cassette. A segmentedbelt 1001 is supported between drive shaft 1002 and idler shaft 1003.Drive shaft 1002 is connected to gear 802, such that belt 1001 is drivenby gear 802, and ultimately by motor 801. Motor 801 (and thus belt 1001)may be driven in either direction. Paddles 1004 are integrally formedwith segments of belt 1001, and circulate within chamber 1005 as thebelt moves. Recesses within drive shaft 1002 and idler shaft 1003 (notvisible) engage with teeth 1006 formed on the inner surface of belt1001, providing positive relationship between the angular position ofdrive shaft 1002 and the travel of belt 1001.

Other arrangements are possible. For example, belt 1001 could be acontinuous belt rather than a segmented belt, and paddles 1004 could beattached to the belt rather than being integrally formed with it.

The spaces between paddles 1004 form a number of storage compartments,some of which are filled with blister packs 901. To dispense an item,belt 1001 is incrementally advanced until the bottommost paddle 1004holding an item approaches a vertical orientation, as shown by paddle1007, and the item falls by gravity through opening 604 to dispensedrawer 107.

While chamber 1005 is shown as being oriented vertically (being tallerthan it is wide), this is not a requirement. A dispensing mechanismaccording to embodiments of the invention may also position a chamber ina horizontal orientation (being wider than it is tall).

FIG. 11 is an oblique detail view of the upper portion of cassette 702,providing more detail about the construction of cassette 702.

The use of paddles 1004 in this manner provides the ability to store alarge number of items to be dispensed, in comparison with prior cassettedesigns, for example the prior helical screw dispenser. Example cassette702 uses 32 paddles 1004, providing storage for up to 30 items betweenpaddles 1004. More or fewer paddles 1004 could be used, providing adifferent number of storage spaces, depending on the sizes of the itemsto be placed in and dispensed from the cassette. While other dimensionsare possible, example cassette 702 is approximately 251 mm tall, 72 mmwide, and 49 mm deep, and thus displaces a volume of less than 900 cubiccentimeters, or about 30 cubic centimeters for each item that can bestored in cassette 702. In other embodiments, more items may be storedby placing paddles 1004 closer together, making paddles 1004 smaller, orby other miniaturization techniques. For example, in variousembodiments, cassette 702 may displace, less than 30, less than 25, lessthan 20, less than 15, or less than 10 cubic centimeters for each itemstored in cassette 702 at full capacity.

In some embodiments, dispensing mechanism 202 may include one or moresensors for directly detecting movement of a mechanical component ofdispensing mechanism 202. For example, the driving gear within dispenser701 may have holes around its main portion, so that the remainingmaterial between the holes functions as broad spokes. A reflectiveoptical sensor may be provided within dispenser 701 that shines light(for example infrared light) onto the driving gear and can detectwhether a return reflection is received. Rotation of the gear thenresults in an alternating signal from the sensor as the reflective“spokes” and the non-reflective holes alternately pass the sensor. Aprocessor or other circuitry within dispenser 701 can interpret thissignal to verify the motion of the driving gear. This direct measurementprovides additional feedback as to the operation of dispensing mechanism202. For example, if it is verified using the additional sensor thatbelt 1001 has moved sufficiently far that an item should be dispensed,but the light curtain sensor does not detect the dispensing of an item,it may be determined that cassette 702 is empty, or it may be suspectedthat an error has occurred.

Other kinds of sensors could be used to directly measure mechanicalmotion. For example, the passing of paddles 1004 may be detected by areflective optical sensor shining light through an opening the wall ofchamber 1005. Preferably, any active parts of the sensing system residein dispenser 701, so that cassette 702 does not include activeelectrical components.

Dispensing Mechanism for Vials and Other Similarly-Shaped Items

FIGS. 12A and 12B illustrate upper and lower partially exploded obliqueviews of dispensing mechanism 204. Dispensing mechanism 204 may beespecially useful in dispensing vials such vial 1301 shown in FIG. 13,having a protruding cylindrical top 1302. Vial 1301 may be used, forexample, for storing fluids for loading into a hypodermic syringe forinjection into a patient. Other similarly-shaped items may also bedispensed by dispensing mechanism 204.

Referring again to FIGS. 12A and 12B, example dispensing mechanismincludes a dispenser 1201 and a cassette 1202, which may be easilyseparable for restocking dispensing mechanism 204.

Preferably, cassette 1202 does not contain any active electricalcomponents. All of the active components of dispensing mechanism 204reside in dispenser 1201. For example, an antenna 1203 can excite apassive memory chip 1204 in cassette 1202, to determine the contents ofcassette 1202 (written into passive memory chip 1204 when cassette 1202was filled at a remote location). If desired, antenna 1203 can also beused to update the data in passive memory chip 1204. This wireless dataexchange may use any suitable wireless protocol, for example Near FieldCommunications (NFC), radio frequency identification (RFID), or anotherwireless protocol.

Dispenser 1201 can preferably automatically detect the installation andremoval of cassette 1202. This automatic detection may facilitate theinventory and tracking of items, and also can help prevent illicitdiversion of items. The detection may be accomplished in any suitableway, for example periodic polling using antenna 1203, a contact sensor(not shown) that can detect the presence of cassette 1202electromechanically, or by another technique. Dispensing mechanism 204may be removably secured to one of rails 201 using a snap mechanism, oneor more screws, or by another method.

In other embodiments, a dispensing mechanism in accordance withembodiments of the invention may not have the separable architecture ofdispensing mechanism 204, but may be a single unit including space forstoring items to be dispense and including an actuator and othercomponents for dispensing items. In other embodiments that do include acassette, the cassette may include active components, for example amotor or other actuator, light emitters for sensing, or othercomponents.

Although not visible in FIGS. 12A and 12B, a light emitter and lightreceivers are positioned near the bottom of dispenser 1201, and operatesimilarly to light emitter 706 and receivers 707 described above withrespect to dispensing mechanism 202. In operation, light from the lightemitter reflects from reflective surface 1205 (visible in FIG. 12B) andreturns to the light receivers, so long as it is not interrupted by anitem being dispensed and falling through the “light curtain” formedacross opening 1206. When an item is dispensed through opening 1206, itinterrupts the light received by either or both light receivers, anddispenser 1201 can note that an item has in fact been dispensed. If nolight interruption is detected despite a command to dispense an item,computer 103 may assume that a misfeed or other problem has occurred, orthat cassette 1202 is empty. By using more sophisticated monitoringstrategies, accidental dispensing of multiple items may be detected. Forexample, if two interruptions of the light curtain are detected closelyspaced in time, a double feed may be indicated.

In other embodiments, the light emitters and receivers may be onopposite sides of opening 1206, so that the receivers receive lightdirectly from the light emitters until the light is interrupted by thedispensing of an item.

As is visible in FIG. 12B, a connector 1207, compatible with connectors302 on rails 201, is positioned to engage one of connectors 302 whendispensing mechanism 204 is installed in restock drawer 106. Althoughnot shown in FIGS. 12A and 12B, dispensing mechanism 204 may include abutton and light similar to button 601 and light 602 discussed above,for communication between a restocking technician or other user andcomputer 103 of cabinet 100.

FIG. 14 is a cutaway oblique view of example cassette 1202, partiallyfilled with vials 1301, and with the top of cassette 1202 removed. As isvisible in FIG. 14, cassette 1202 includes a number of T-shaped verticalchannels 1401 of a shape and size to receive cylindrical tops 1302 of anumber of vials 1301 and hold the vials in vertical stacks. Vials 1301may be, for example, 5 ml vials, having a diameter of about 22 mm, aheight of about 42.5 mm. While other dimensions may be used, examplecassette 1202 is about 212 mm high, 72 mm wide, and 49 mm deep(displacing about 750 cubic centimeters), and can hold 27 vials of the 5ml size. Thus, example cassette 1202 displaces less than 28 cubiccentimeters for each vial that can be stored in cassette 1202. In otheruses, 1 ml vials may be used, having a diameter of about 15 mm, in whichcase cassette 1202 may hold about 39 of the 1 ml vials, for adisplacement of less than 20 cubic centimeters for each vial that can bestored in cassette 1202. Other vial sizes may be used as well. Theprotruding cylindrical tops of the various vial sizes are preferablysimilar enough that any compatible size vial can be retained by verticalchannels 1401. In various embodiments, cassette 1202 may displace lessthan 30, less than 25, less than 20, or less than 15 cubic centimetersfor each vial stored in cassette 1202 at full capacity.

FIG. 15 illustrates a lower oblique view of loaded cassette 1202,showing spring-loaded latches 1501. While cassette 1202 is separatedfrom dispenser 1201, latches 1501 partially block T-shaped channels1401, preventing vials 1301 from falling out of cassette 1202. Latches1501 are connected to a latch release 1502, which when actuated in thedirection shown, moves latches out of channels 1401. When cassette 1202is installed in dispenser 1201, latch release 1502 can be moved andrestrained, so that vials 1301 are free to travel down T-shaped channels1401, as is described in more detail below.

FIG. 16 illustrates a partially-cutaway rear view of the lower portionof dispenser 1201. As is visible in FIG. 16, a motor 1601 turns a shaftthrough right-angle gears 1602. Motor 1601 may be, for example, astepper motor or a simple DC or AC motor, operated in the mannerdescribed above in relation to dispensing mechanism 202. That is, motor1601 may be incrementally advanced either by control of the steps of astepper motor, or by running motor 1601 only until the dispensing of anitem is detected.

In other embodiments, an actuator other than a motor may be used. Forexample, a solenoid or memory metal actuator may provide a reciprocatingmotion that is used to drive the gear within dispenser 1201 using aratchet or ratchet-like arrangement. Other kinds of actuators anddriving arrangements are possible.

FIG. 17 illustrates a front view of the lower portion of dispenser 1201,showing additional details of its operation. A central slotted gear 1701is driven directly by right angle gears 1602. While a rotation directionis shown for ease of explanation, the choice of rotation direction isarbitrary, and either direction may be used. slotted gear 1701 drivesslotted gears 1702 and 1703. Each of the slotted gears has a T-shapedblind slot 1704 of a shape and size to receive the cylindrical top of avial 1301. Here, “blind” means that the slot does not continue all theway through the slotted gear.

As the slotted gears rotate, the respective slots 1704 “take turns”reaching an upward vertical orientation and a downward verticalorientation. For example, the three slotted gears of example dispenser1201 are meshed in such a way that one of the T-shaped slots reaches theupward vertical orientation for every 120 degrees of rotation of centralslotted gear 1701. If different numbers of slotted gears are present,then a different angular separation of the gear positions may be used,but preferably slots 1704 reach the downward vertical orientation atevenly spaced angular intervals of the driving gear 1701.

When one of the slots reaches its upward vertical orientation and atleast one vial is present in the corresponding T-shaped vertical channelof cassette 1202 (not shown), the vial is free to drop into the T-shapedblind slot 1704 of the respective slotted gear. In FIG. 17, slotted gear1701 has just received a vial 1301 in this manner. Slotted gear 1703 haspreviously received a vial 1705. As the gears continue to turn, the slotin slotted gear 1702 approaches its downward vertical orientation. Whenthe downward vertical orientation is reached, vial 1705 will be free todrop through opening 1206 into dispense drawer 107. Slot 1704 of slottedgear 1703 is approaching its upward vertical orientation, to receiveanother vial, if one is present. Thus, the vials in cassette 1202 can bedispensed one by one.

In some embodiments, dispensing mechanism 204 may include one or moresensors for directly detecting movement of a mechanical component ofdispensing mechanism 204. For example, the driven gear within dispenser1201 may have holes around its main portion, so that the remainingmaterial between the holes functions as broad spokes. A reflectiveoptical sensor may be provided within dispenser 1201 that shines light(for example infrared light) onto the driving gear and can detectwhether a return reflection is received. Rotation of the gear thenresults in an alternating signal from the sensor as the reflective“spokes” and the non-reflective holes alternately pass the sensor. Aprocessor or other circuitry within dispenser 1201 can interpret thissignal to verify the motion of the driven gear. This direct measurementprovides additional feedback as to the operation of dispensing mechanism204. For example, if it is verified using the additional sensor that thegear has moved sufficiently far that an item should be dispensed (120degrees in the example embodiment), but the light curtain sensor doesnot detect the dispensing of an item, it may be determined that cassette1202 is empty, or it may be suspected that an error has occurred.

Other kinds of sensors could be used to directly measure mechanicalmotion. For example, the teeth of slotted gear 1702 or 1703 may bevisible to a reflective optical sensor shining light through an openingthe wall of dispenser 1201, and the rotation of the slotted gears may bedetected by monitoring the passing of the individual gear teeth.Preferably, any active parts of the sensing system reside in dispenser1201, so that cassette 1202 does not include active electricalcomponents.

Dispenser for Syringes and Other Similarly-Shaped Items

FIGS. 18A and 18B illustrate upper and lower views of dispensingmechanism 203 in more detail. Dispensing mechanism 203 may be especiallyuseful for dispensing cylindrical items such as syringes, althoughdispensing mechanism 203 may be useful for dispensing othersimilarly-shaped items as well.

Example dispensing mechanism 203 comprises a dispenser 1801 and acassette 1802, which are separable. For example, dispenser 1801 andcassette 1802 may snap together, may be separable with the removal ofone or a small number of screws, or may be reasonably separable in someother way without damage to either dispenser 1801 or cassette 1802. Inthis way, restocking may be accomplished by replacing a depletedcassette 1802 with a full cassette 1802.

As is visible in FIG. 18B, a connector 1803, compatible with connectors302 on rails 201, is positioned to engage one of connectors 302 whendispensing mechanism 203 is installed in restock drawer 106. Dispenser1801 defines an opening 1804 at the bottom of dispensing mechanism 203,through which items are dispensed. Dispensing mechanism 203 may beremovably secured to one of rails 201 using a snap mechanism, one ormore screws, or by another method.

Preferably, cassette 1802 does not contain any active electricalcomponents. All of the active components of dispensing mechanism 203reside in dispenser 1801. For example, an antenna 1805 can excite apassive memory chip 1806 in cassette 1802, to determine the contents ofcassette 1802 (written into passive memory chip 1806 when cassette 1802was filled at a remote location). If desired, antenna 1805 can also beused to update the data in passive memory chip 1806. This wireless dataexchange may use any suitable wireless protocol, for example Near FieldCommunications (NFC), radio frequency identification (RFID), or anotherwireless protocol.

Dispenser 1801 can preferably automatically detect the installation andremoval of cassette 1802. This automatic detection may facilitate theinventory and tracking of items, and also can help prevent illicitdiversion of items. The detection may be accomplished in any suitableway, for example periodic polling using antenna 1805, a contact sensor(not shown) that can detect the presence of cassette 1802electromechanically, or by another technique.

In other embodiments, a dispensing mechanism in accordance withembodiments of the invention may not have the separable architecture ofdispensing mechanism 203, but may be a single unit including space forstoring items to be dispense and including an actuator and othercomponents for dispensing items. In other embodiments that do include acassette, the cassette may include active components, for example amotor or other actuator, light emitters for sensing, or othercomponents.

A light emitter 1807 and two light receivers 1808 are positioned nearthe bottom of dispenser 1801. In operation, light from light emitter1807 reflects from a reflective surface of dispenser 1801 (not visiblein FIGS. 18A and 18B, but opposite light emitter 1807 and receivers1808) and returns to light receivers 1808, so long as it is notinterrupted by an item being dispensed and falling through the “lightcurtain” formed across opening 1804. When an item is dispensed throughopening 1804, it interrupts the light received by either or both oflight receivers 1808, and dispenser 1801 can note that an item has infact been dispensed. If no light interruption is detected despite acommand to dispense an item, computer 103 may assume that a misfeed orother problem has occurred, or that cassette 1802 is empty. By usingmore sophisticated monitoring strategies, accidental dispensing ofmultiple items may be detected. For example, if two interruptions of thelight curtain are detected closely spaced in time, a double feed may beindicated. Emitter 1807 may be of any suitable type of emitter, and mayemit light in any suitable wavelength or combinations of wavelengths.For example, light emitter 1807 may be a light emitting diode, a lasersuch as a vertical cavity semiconductor emitting laser (VCSEL) oranother kind of light source, and may emit visible light, infraredlight, or light in other suitable wavelength bands or combinations ofwavelength bands.

In other embodiments, light emitter 1807 and receivers 1808 may be onopposite sides of opening 1804, so that receivers 1808 receive lightdirectly from light emitter 1807 until the light is interrupted by thedispensing of an item.

A clear window 1809 may be provided, so that a user can see the contentsof cassette 1802.

Although not shown in FIGS. 18A and 18B, a button and light similar tobutton 601 and light 602 discussed above, for communication between arestocking technician or other user and computer 103 of cabinet 100.

FIG. 19 shows an oblique view of dispenser 1801 with some parts removed,revealing internal details of the operation of dispenser 1801. A cable1901 connects a first circuit board 1902 with a second circuit board1903, to which a motor 1904 is connected. Motor 1904 may be, forexample, a stepper motor whose angular position can be readily movedincrementally and held. In that case, an item may be dispensed byadvancing motor 1904 by one rotation. If the light curtain does notdetect that an item is dispensed, motor 1904 may be advanced further,and if no dispensing is yet detected, an error message may be generated,or it may be assumed that cassette 1802 is empty. Alternatively, motor1904 may be a simple DC or AC motor, in which case dispensing may beaccomplished by simply running motor 1904 until the dispensing of anitem is detected, and then shutting off the motor. A time limit may beimposed, such that if no dispensing is detected within the time limitwith motor 1904 running, the motor may be shut off and an error messagegenerated.

Motor 1904 turns a cam 1905 in the direction shown, the function ofwhich is explained in more detail below.

A microprocessor, microcontroller, or similar controlling circuitry mayreside within dispenser 1801, and may operate the various activecomponents and sensors of dispenser 1801 in response to high-levelcommands from a supervisory controller elsewhere within restock drawer106, or from computer 103. In that case, dispenser 1801 is considered a“smart” dispenser, because it includes some processing intelligence.However, other architectures are possible. For example, logic signalsfrom a supervisory controller elsewhere within restock drawer 106 mayoperate dispenser 1801.

As was discussed above, dispensing mechanism 203 may be especiallyuseful for dispensing syringes or other similarly-shaped items. FIG. 20illustrates a typical syringe 2000 of a kind that may be dispensed bydispensing mechanism 203. Syringe 2000 has a main barrel 2001 configuredto hold a quantity of a serum or other liquid, and a reduced diameterportion 2002 configured to accept a hypodermic needle or the like. Insome embodiments, the outer diameter of main barrel portion may be about11.2 mm, and the overall length of syringe 2000 may be in keeping withthe capacity of syringe 2000. For example, a syringe 2000 configured tohold 1 ml of liquid may have an overall length of about 115 mm, while asyringe 2000 configured to hold 2 ml of liquid may have an overalllength of about 148 mm. These dimensions are given only as examples, andsyringes or other items having different sizes may be used inembodiments of the invention.

FIGS. 21A and 21B illustrate cassette 1802 with certain outer panelsremoved, and revealing internal details of cassette 1802. In FIG. 21A,cassette 1802 is empty, and in FIG. 21B, cassette 1802 contains a numberof syringes 2000. An angled floor 2101 of cassette 1802 and an angledmoveable guide 2102 serve to funnel syringes 2000 toward the lowest part2013 of cassette 1802, to be dispensed in the manner described below.While other dimensions are possible, example cassette 1802 is about 234mm high, 71 mm deep, and 153 mm wide, and thus displaces an overallvolume of less than 2600 cubic centimeters, and can hold up to 120 ormore syringes 2000. Cassette 1802 thus displaces less than 22 cubiccentimeters for each syringe that can be stored in cassette 1802. Whilesyringes 2000 having a 2 ml capacity are shown, cassette 1802 may beconfigured to dispense syringes having a smaller overall length byplacing a spacer block (not shown) within cassette 1802. In variousembodiments, cassette 1802 may displace less than 25, less than 20, lessthan 15, or less than 10 cubic centimeters for each item stored incassette 1802 at full capacity.

FIGS. 22A-22C illustrate a cutaway view of portions of dispenser 1801and cassette 1802 and their operation to dispense a syringe. A bottomtray 2201 of cassette 1802 defines an opening 2202 and a ledge 2203. Amovable slide 2204 defines a slot in which syringe 2000 a is positionedin FIG. 22A. Slide 2204 is biased to the left by spring 2205, such thatsyringe 2000 a remains suspended by ledge 2203. Syringe 2000 a is inposition to be dispensed, while cassette 1802 contains additionalsyringes such as syringe 2000 b. Spring 2205 also ensures that thesyringes in cassette 1802 are not accidentally dispensed when cassette1802 is separated from dispenser 1801, for example during transport froma central pharmacy to cabinet 100.

When it is desired to dispense a syringe, motor 1904 (not visible inFIGS. 22A-22C) turns cam 1905 as shown in FIG. 22B. Cam 1905 actsagainst surface 2206 of slide 2204, moving slide 2204 to the right,aligning the slot in slide 2204 with opening 2202 in bottom tray 2201 ofcassette 1802. Syringe 2000 a can accordingly drop through opening 2202and into dispense drawer 107. Syringe 2000 b rolls down angled floor2010 into position between slide 2204 and angled floor 2101. Guide 2102is force upward by its interaction with slide 2204, to jostle anyremaining syringes within cassette 1802, facilitating their futuredispensing.

In FIG. 22C, cam 1905 has rotated past its contact with slide 2204,allowing spring 2205 to force slide 2204 back to its nominal position.Sensor electronics may sense the dispensing of syringe 2000 a, or thatslide 2204 is back to its nominal position, and may shut off motor 1904,stopping cam 1905. Syringe 2000 b drops into the slot in slide 2204,resting on ledge 2203, in preparation for its future dispensing.

In other embodiments, an actuator other than a motor may be used. Forexample, a solenoid or memory metal actuator may provide a translationalmotion that is used to directly translate slide 2204 against spring2205. Other kinds of actuators and driving arrangements are possible.

In some embodiments, dispensing mechanism 203 may include one or moresensors for directly detecting movement of a mechanical component ofdispensing mechanism 203. For example, slide 2204 may be generallynon-reflective, but may include a reflective sticker placed fordetection by a reflective optical when slide 2204 moves under the actionof cam 1905. The passing of the reflective sticker, as detected by thesensor, verifies that slide 2204 has actually moved. A similar effectmay be achieved by placing a magnet on slide 2204 and detecting itspassing of a Hall Effect sensor. Similarly, the movement of cam 1905could be directly sensed. A processor or other circuitry withindispenser 1801 can interpret a signal produced by the sensor to verifythe motion of the slide or cam. This direct measurement providesadditional feedback as to the operation of dispensing mechanism 203. Forexample, if it is verified using the additional sensor that slide 2204has moved sufficiently far that an item should be dispensed, but thelight curtain sensor does not detect the dispensing of an item, it maybe determined that cassette 1802 is empty, or it may be suspected thatan error has occurred.

FIG. 23 illustrates an electrical block diagram of dispensing unit 105,in accordance with embodiments of the invention. Among other components,dispensing unit 105 includes a main PCBA 2301, and a number of railassemblies 201, each of which includes a respective PCBA. Only onegeneric dispensing mechanism 2302 is shown, but it will be recognizedthat a number of dispensing mechanisms such as dispensing mechanisms202, 203, and 204 may be present. Each dispensing mechanism may have itsown PCBA 2303.

FIG. 24 illustrates a more detailed electrical block diagram of restockdrawer 106 main PCBA 2301, in accordance with embodiments of theinvention. Main PCBA 2301 include a microcontroller 2401, as well asvarious sensing and communication circuitry, and connections 2402 forconnection to rail assemblies 201.

FIG. 25 illustrates a more detailed electrical block diagram of adispenser PCBA 2303, in accordance with embodiments of the invention. Inthis example, the dispenser includes a microcontroller 2501, and thedispenser represented is a “smart” dispenser. Dispenser PCBA 2303 alsoincludes various power and communication circuitry, driver circuitry fora motor, a wireless communication interface and antenna, various othersensors, and other components, many of which may be described above inrelation to dispensers 701, 1201, and 1801.

Additional Dispensing Mechanism for Blister Packs and Other Small Items

FIGS. 26A and 26B illustrate a dispensing mechanism 2600 in accordancewith other embodiments of the invention. Dispensing mechanism 2600 issimilar in some ways to dispensing mechanism 202 described above, andmay be especially useful for dispensing small items such as individualmedicine doses packaged in well-known “blister packs” such as blisterpack 901, although dispensing mechanism 2600 may be useful fordispensing may other kinds of items as well. Like dispensing mechanism202, dispensing mechanism 2600 may include one or more buttons orlights, and may have an internal processor that controls the operationof dispensing mechanism 2600. Dispensing mechanism 2600 includes aconnector 2601, compatible with connectors 302 on rails 201 andpositioned to engage one of connectors 302 when dispensing mechanism 202is installed in restock drawer 106. Various parts of dispensingmechanism 2600 collectively constitute a housing that defines an opening2602 at the bottom of dispensing mechanism 2600, through which items aredispensed. Dispensing mechanism 2600 may be removably secured to one ofrails 201 using a snap mechanism, one or more screws, or by anothermethod.

As is shown in FIGS. 27A and 27B, example dispensing mechanism 2600comprises a dispenser 2701 and a cassette 2702, which are separable. Forexample, dispenser 2701 and cassette 2702 may snap together, may beseparable with the removal of one or a small number of screws, or may bereasonably separable in some other way without damage to eitherdispenser 2701 or cassette 2702. In this way, restocking may beaccomplished by replacing a depleted cassette 2702 with a full cassette2702. A gear 2703 engages a driving gear (not easily visible in FIG.27A) within dispenser 2701 when cassette 2702 is assembled to dispenser2701.

Preferably, as will be discussed in more detail below, cassette 2702does not contain any active electrical components. All of the activecomponents of example dispensing mechanism 2600 reside in dispenser2701. For example, an antenna 2704 can excite a passive memory chip 2705in cassette 2702, to determine the contents of cassette 2702 (writteninto passive memory chip 2705 when cassette 2702 was filled at a remotelocation). If desired, antenna 2704 can also be used to update the datain passive memory chip 2705. This wireless data exchange may use anysuitable wireless protocol, for example Near Field Communications (NFC),radio frequency identification (RFID), or another wireless protocol.

Dispenser 2701 can preferably automatically detect the installation andremoval of cassette 2702. This automatic detection may facilitate theinventory and tracking of items, and also can help prevent illicitdiversion of items. The detection may be accomplished in any suitableway, for example periodic polling using antenna 2704, a contact sensor(not shown) that can detect the presence of cassette 2702electromechanically, or by another technique.

In other embodiments, a dispensing mechanism in accordance withembodiments of the invention may not have the separable architecture ofdispensing mechanism 2600, but may be a single unit including space forstoring items to be dispense and including an actuator and othercomponents for dispensing items. In other embodiments that do include acassette, the cassette may include active components, for example amotor or other actuator, light emitters for sensing, or othercomponents.

As are visible in FIG. 27A, one or more light emitters 2706 and lightreceivers 2707 are positioned near the bottom of dispenser 2701. Inoperation, light from light emitters 2706 reflects from reflectivesurface 2708 (visible in FIG. 27B) and returns to light receivers 2707,so long as it is not interrupted by an item being dispensed and fallingthrough the “light curtain” formed across opening. When an item isdispensed through opening 2604, it interrupts the light received by anyof light receivers 2707, and dispenser 2701 can note that an item has infact been dispensed. If no light interruption is detected despite acommand to dispense an item, computer 103 may assume that a misfeed orother problem has occurred, or that cassette 2702 is empty. By usingmore sophisticated monitoring strategies, accidental dispensing ofmultiple items may be detected. For example, if two interruptions of thelight curtain are detected closely spaced in time, a double feed may beindicated. Emitter 2706 may be of any suitable type of emitter, and mayemit light in any suitable wavelength or combinations of wavelengths.For example, light emitter 2706 may be a light emitting diode, a lasersuch as a vertical cavity semiconductor emitting laser (VCSEL) oranother kind of light source, and may emit visible light, infraredlight, or light in other suitable wavelength bands or combinations ofwavelength bands. In other embodiments, surface 2708 may benon-reflective, for example black, and the dispensing of an item may bedetected by noting an increase in the intensity of light reachingreceivers 2707, rather than a decrease, as light is reflected from theitem being dispensed.

In other embodiments, light emitters 2706 and receivers 2707 may be onopposite sides of opening 2604, so that receivers 2707 receive lightdirectly from light emitters 2706 until the light is interrupted by thedispensing of an item.

FIG. 28 shows an oblique view of dispensing mechanism 2600 with someparts removed, revealing some internal details of dispenser 2701. Amotor 2801 having a right-angle drive turns driving gear 2802, whichengages gear 2703 on cassette 2702 to actuate cassette 2702. Motor 2801may be, for example, a stepper motor whose angular position can bereadily moved incrementally and held. In that case, an item may bedispensed by advancing motor 2801 by a number of steps known tocorrespond to one dispensing operation. If the light curtain does notdetect that an item is dispensed, motor 2801 may be advanced further,and if no dispensing is yet detected, an error message may be generated,or it may be assumed that cassette 2702 is empty. Alternatively, motor2801 may be a simple DC or AC motor, in which case dispensing may beaccomplished by simply running motor 2801 until the dispensing of anitem is detected, and then shutting off the motor so that motor 2801 isadvanced incrementally as far as is needed. A time limit may be imposed,such that if no dispensing is detected within the time limit with motor2801 running, the motor may be shut off and an error message generated.

In other embodiments, an actuator other than a motor may be used. Forexample, a solenoid or memory metal actuator may provide a reciprocatingmotion that is used to drive the driving gear within dispenser 2701using a ratchet or ratchet-like arrangement. Other kinds of actuatorsand driving arrangements are possible.

A microprocessor, microcontroller, or similar controlling circuitry mayreside within dispenser 2701, and may operate the various activecomponents and sensors of dispenser 2701 in response to high-levelcommands from a supervisory controller elsewhere within restock drawer106, or from computer 103. In that case, dispenser 2701 is considered a“smart” dispenser, because it includes some processing intelligence.However, other architectures are possible. For example, logic signalsfrom a supervisory controller elsewhere within restock drawer 106 mayoperate dispenser 2701.

FIG. 29 shows an orthogonal view of cassette 2702, with its back coverremoved, and showing the internal workings of the cassette. A segmentedbelt 2901 is supported between drive shaft 2902 and idler shaft 2903.Drive shaft 2902 is connected to gear 2802, such that belt 2901 isdriven by gear 2802, and ultimately by motor 2801. Motor 2801 (and thusbelt 2901) may be driven in either direction. Paddles 2904 areintegrally formed with segments of belt 2901, and form links in belt2901. Paddles 2904 circulate within chamber 2905 as belt 2901 moves. Asprocket 2906 turns with drive shaft 2902 to drive belt 2901, providingpositive relationship between the angular position of drive shaft 2902and the travel of belt 2901.

The spaces between paddles 2904 form a number of storage compartments,some of which are filled with blister packs 901. To dispense an item,belt 2901 is incrementally advanced until the bottommost paddle 2904holding an item approaches a vertical orientation, as shown by paddle2907, and the item falls by gravity through opening 2602 to dispensedrawer 107.

While chamber 2905 is shown as being oriented vertically (being tallerthan it is wide), this is not a requirement. A dispensing mechanismaccording to embodiments of the invention may also position a chamber ina horizontal orientation (being wider than it is tall).

Sprocket 2906 is non-circular. That is, its cross section takenperpendicular to its axis of rotation is not circular. In the example ofFIG. 29, sprocket 2906 has a square cross section.

FIG. 30 shows sprocket 2906 and several paddles in a partially explodedview. Sprocket 2906 is outlined in dashed lines 3001 to show its squarecross section. Particular paddles 2904 a, 2904 b, 2904 c, and 2904 dhave been moved from their assembled positions, for clarity ofexplanation. Each of paddles 2904 a-2904 d is L-shaped. Paddles 2904 aand 2904 b join together, for example using pins, at the tips 3002 oftheir L shapes, and paddles 2904 b and 2904 c join together at thecorners 3003 of their L shapes. Similarly paddles 2904 a and 2904 e arejoined at their corners 3004, and paddles 2904 d and 2904 f are joinedat their corners 3005. Thus, the paddles are joined together inalternating orientation along the length of belt 2901.

This arrangement allows the adjacent pairs of paddles definingcompartments for holding items to be dispensed to remain closer togetheras they traverse the top of cassette 2702 than if sprocket 2906 wereround. The spacing between paddles 2904 c and 2904 d is labeled “D” inFIG. 31. The paddles do not necessarily maintain parallelism throughtheir traversal of the top of cassette 2702, but remain closer than ifsprocket 2906 were round. This arrangement may reduce the possibility ofjamming of the cassette mechanism.

Referring again to FIG. 29, a spring-loaded idler 2908 maintains tensionon belt 2901, and takes up the unevenness of the travel of belt 2901over square sprocket 2906.

The use of paddles 2904 in this manner provides the ability to store alarge number of items to be dispensed, in comparison with prior cassettedesigns, for example the prior helical screw dispenser. Example cassette2702 uses 28 pairs paddles 1004, providing storage for up to about 26items between paddles 2904. More or fewer paddles 2904 could be used,providing a different number of storage spaces, depending on the sizesof the items to be placed in and dispensed from the cassette. Whileother dimensions are possible, example cassette 2702 is approximately251 mm tall, 72 mm wide, and 49 mm deep, and thus displaces a volume ofless than 900 cubic centimeters, or about 34.6 cubic centimeters foreach item that can be stored in cassette 2702. In other embodiments,more items may be stored by placing paddles 2904 closer together, makingpaddles 2904 smaller, or by other miniaturization techniques. Forexample, in various embodiments, cassette 2702 may displace, less than30, less than 25, less than 20, less than 15, or less than 10 cubiccentimeters for each item stored in cassette 2702 at full capacity.

In some embodiments, dispensing mechanism 2600 may include one or moresensors for directly detecting movement of a mechanical component ofdispensing mechanism 2600. For example, the driving gear withindispenser 2701 may have holes around its main portion, so that theremaining material between the holes functions as broad spokes. Areflective optical sensor may be provided within dispenser 2701 thatshines light (for example infrared light) onto the driving gear and candetect whether a return reflection is received. Rotation of the gearthen results in an alternating signal from the sensor as the reflective“spokes” and the non-reflective holes alternately pass the sensor. Aprocessor or other circuitry within dispenser 2701 can interpret thissignal to verify the motion of the driving gear. This direct measurementprovides additional feedback as to the operation of dispensing mechanism2600. For example, if it is verified using the additional sensor thatbelt 2901 has moved sufficiently far that an item should be dispensed,but the light curtain sensor does not detect the dispensing of an item,it may be determined that cassette 2702 is empty, or it may be suspectedthat an error has occurred.

Other kinds of sensors could be used to directly measure mechanicalmotion. For example, the passing of paddles 2904 may be detected by areflective optical sensor shining light through an opening the wall ofchamber 2905. Preferably, any active parts of the sensing system residein dispenser 2701, so that cassette 2702 does not include activeelectrical components.

FIG. 32 shows a rear oblique view of cassette 2702, and FIG. 33 shows amagnified view of part of FIG. 32. FIGS. 32 and 33 illustrate a brake3201. Brake 3201 is normally engaged, and hinders movement of belt 2901when engaged. In this example, teeth 3301 in brake 3201 engage with theteeth of gear 2703 on cassette 2702. This may be helpful, for example,during shipment or transport of a full cassette, to prevent intentionalor accidental removal of items from cassette 2702 by turning gear 2703.

Preferably, brake 3201 disengages automatically when cassette 2702 ininstalled into dispenser 2701. For example, tab 3303 on brake 3201 maycontact the top of dispenser 2701 as cassette 2702 is installed intodispenser 2701, lifting brake 3201 out of engagement with gear 2703.

Other measures may be taken to prevent accidental or intentionaldiversion of items from cassette 2702. For example, as shown in FIG. 34,openings 3401 may be provided in back 3402 and side 3403 of cassette2702, to accommodate tamper-evident ties that also disable the operationof cassette 2702. FIG. 35 shows cassette 2702 (with back 3402 removed)with several ties 3501 installed. Ties 3501 may be, for example, plastic“zip” ties or a similar kind of tie, that is not conveniently removablewithout cutting the tie. Ties 3501 may be installed when cassette isfilled, and not legitimately removed until cassette 2702 is ready to beinstalled in a drawer such as drawer 106. If cassette 2702 arrives atits destination with all of ties 3501 intact, it may be assumed that notampering or accidental dispensing has occurred. If any of ties 3501 ismissing or damaged, diversion may be suspected. When a decision is madeto install cassette 2702 in a dispenser or drawer, the restocktechnician can cut ties 3501 before installation.

Other kinds of tamper-evident mechanisms may be used as well, instead ofor in addition to ties 3501.

Additional Dispensing Mechanism for Vials and Other Similarly-ShapedItems

FIGS. 36A and 36B illustrate upper and lower partially exploded obliqueviews of a dispensing mechanism 3600, in accordance with embodiments ofthe invention. Dispensing mechanism 3600 is similar in some ways todispensing mechanism 204 described above, and may be especially usefulin dispensing vials such vial 1301 shown in FIG. 13, having a protrudingcylindrical top 1302. Vial 1301 may be used, for example, for storingfluids for loading into a hypodermic syringe for injection into apatient. Other similarly-shaped items may also be dispensed bydispensing mechanism 3600.

Referring again to FIGS. 36A and 36B, example dispensing mechanismincludes a dispenser 3601 and a cassette 3602, which may be easilyseparable for restocking dispensing mechanism 3600.

Preferably, cassette 3602 does not contain any active electricalcomponents. All of the active components of dispensing mechanism 3600reside in dispenser 3601. For example, an antenna 3603 can excite apassive memory chip 3604 in cassette 3602, to determine the contents ofcassette 3602 (written into passive memory chip 3604 when cassette 3602was filled at a remote location). If desired, antenna 3603 can also beused to update the data in passive memory chip 3604. This wireless dataexchange may use any suitable wireless protocol, for example Near FieldCommunications (NFC), radio frequency identification (RFID), or anotherwireless protocol.

Dispenser 3601 can preferably automatically detect the installation andremoval of cassette 3602. This automatic detection may facilitate theinventory and tracking of items, and also can help prevent illicitdiversion of items. The detection may be accomplished in any suitableway, for example periodic polling using antenna 3603, a contact sensor(not shown) that can detect the presence of cassette 3602electromechanically, or by another technique. Dispensing mechanism 3600may be removably secured to one of rails 201 using a snap mechanism, oneor more screws, or by another method.

In other embodiments, a dispensing mechanism in accordance withembodiments of the invention may not have the separable architecture ofdispensing mechanism 3600, but may be a single unit including space forstoring items to be dispense and including the actuator and othercomponents for dispensing items. In other embodiments that do include acassette, the cassette may include active components, for example amotor or other actuator, light emitters for sensing, or othercomponents.

Although not visible in FIGS. 36A and 36B, a light emitter and lightreceivers are positioned near the bottom of dispenser 3601, and operatesimilarly to light emitter 706 and receivers 707 described above withrespect to dispensing mechanism 202. In operation, light from the lightemitter reflects from reflective surface 3605 (visible in FIG. 12B) andreturns to the light receivers, so long as it is not interrupted by anitem being dispensed and falling through the “light curtain” formedacross opening 3606. When an item is dispensed through opening 3606, itinterrupts the light received by either or both light receivers, anddispenser 3601 can note that an item has in fact been dispensed. If nolight interruption is detected despite a command to dispense an item,computer 103 may assume that a misfeed or other problem has occurred, orthat cassette 3602 is empty. By using more sophisticated monitoringstrategies, accidental dispensing of multiple items may be detected. Forexample, if two interruptions of the light curtain are detected closelyspaced in time, a double feed may be indicated. In other embodiments,surface 3605 may be non-reflective, for example black, and thedispensing of an item may be detected by noting an increase in theintensity of light reaching the receivers, rather than a decrease, aslight is reflected from the item being dispensed.

In other embodiments, the light emitters and receivers may be onopposite sides of opening 3606, so that the receivers receive lightdirectly from the light emitters until the light is interrupted by thedispensing of an item.

As is visible in FIG. 36B, a connector 3607, compatible with connectors302 on rails 201, is positioned to engage one of connectors 302 whendispensing mechanism 3600 is installed in restock drawer 106. Althoughnot shown in FIGS. 36A and 36B, dispensing mechanism 3600 may include abutton and light similar to button 601 and light 602 discussed above,for communication between a restocking technician or other user andcomputer 103 of cabinet 100.

FIG. 37 is a cutaway oblique view of example cassette 3602, partiallyfilled with vials 1301, and with the top of cassette 3602 removed. As isvisible in FIG. 37, cassette 3602 includes a number of vertical channels3701 of a shape and size to receive a number of vials 1301 and hold thevials in vertical stacks. In cassette 3602, three vertical channels 3701are present, and vials 1301 are 2 ml vials, having a diameter of about15 mm, and a height of about 35.5 mm. While other dimensions may beused, example cassette 3602 is about 232 mm high, 72 mm wide, and 54 mmdeep (displacing about 902 cubic centimeters), and can hold about 30vials of the 2 ml size. Thus, example cassette 3602 displaces less than31 cubic centimeters for each vial that can be stored in cassette 3602.In other uses, 1 ml vials may be used, having a diameter of about 15 mm,in which case cassette 3602 may hold a similar number of vials. Othervial sizes may be used as well. Walls 3702 divide the stacks of vials,and protrusions 3703 may help constrain the vials by their necks. Invarious embodiments, cassette 3602 may displace less than 30, less than25, less than 20, or less than 15 cubic centimeters for each vial storedin cassette 3602 at full capacity.

Cassette 3602 also includes a number of open-sided rotatable receivers3704 at the bottom of vertical channels 3701.

FIG. 38 illustrates a lower oblique rear view of cassette 3602, showinga set of gears 3801, each of which is coupled to one of open-sidedrotatable receivers 3704. Gears 3801 mesh, so that receivers 3704 rotatein synchronization.

FIG. 39A illustrates a partially-cutaway rear view of dispenser 3601,and FIG. 39B illustrates an oblique front view of dispenser 3601.Referring to both FIGS. 39A and 39B, a motor 3901 drives a belt 3902,which in turn drives gear 3903. Motor 3901 may be, for example, astepper motor or a simple DC or AC motor, operated in the mannerdescribed above in relation to dispensing mechanism 202. That is, motor3901 may be incrementally advanced either by control of the steps of astepper motor, or by running motor 3901 only until the dispensing of anitem is detected. In other embodiments, an actuator other than a motormay be used. For example, a solenoid or memory metal actuator mayprovide a reciprocating motion that is used to drive the gear withindispenser 3601 using a ratchet or ratchet-like arrangement. Other kindsof actuators and driving arrangements are possible.

When dispenser 3601 and cassette 3602 are engaged, gear 3903 meshesdirectly or indirectly with gears 3801 of cassette 3602, to turnopen-sided rotatable receivers 3704. Referring again to FIGS. 37 and 38,gears 3801 rotate in synchronization. While a rotation direction isshown for ease of explanation, the choice of rotation direction isarbitrary, and either direction may be used.

As the gears rotate, the respective open sides of receivers 3704 “taketurns” reaching an upward vertical orientation and a downward verticalorientation. For example, the three gears of example cassette 3602 aremeshed in such a way that one of the receivers reaches the upwardvertical orientation for every 120 degrees of rotation of gears 3801. Ifdifferent numbers of gears are present, then a different angularseparation of the gear positions may be used, but preferably receivers3704 reach the downward vertical orientation at evenly spaced angularintervals gears 3801.

When one of the receivers reaches its upward vertical orientation and atleast one vial is present in the corresponding vertical channel ofcassette 3602 (not shown), the vial is free to drop into the respectivereceiver 3704. As the gears continue to turn, the receivers 3704alternately reach their upward positions to receive vials, and reachtheir downward positions to dispense vials. Thus, the vials in cassette3602 can be dispensed one by one.

In some embodiments, dispensing mechanism 3600 may include one or moresensors for directly detecting movement of a mechanical component ofdispensing mechanism 3600. For example, the driven gear within cassette3602 may have holes around its main portion, so that the remainingmaterial between the holes functions as broad spokes. A reflectiveoptical sensor may be provided within dispenser 3601 that shines light(for example infrared light) onto the driven gear and can detect whethera return reflection is received. Rotation of the gear then results in analternating signal from the sensor as the reflective “spokes” and thenon-reflective holes alternately pass the sensor. A processor or othercircuitry within dispenser 3601 can interpret this signal to verify themotion of the driven gear. This direct measurement provides additionalfeedback as to the operation of dispensing mechanism 3600. For example,if it is verified using the additional sensor that the gear has movedsufficiently far that an item should be dispensed (120 degrees in theexample embodiment), but the light curtain sensor does not detect thedispensing of an item, it may be determined that cassette 3602 is empty,or it may be suspected that an error has occurred.

Other kinds of sensors could be used to directly measure mechanicalmotion. For example, the teeth of gears 3801 may be visible to areflective optical sensor shining light through an opening the wall ofdispenser 3601, and the rotation of the gears may be detected bymonitoring the passing of the individual gear teeth. Preferably, anyactive parts of the sensing system reside in dispenser 3601, so thatcassette 3602 does not include active electrical components.

While cassette 3602 is shown as having three vertical channels 3701,other numbers of channels may be used. For example, an alternatecassette may have two vertical channels, and may be suitable fordispensing 5 ml vials having a diameter of about 25 mm.

Referring again to FIG. 37, a hinged flap 3705 can be seen belowrotatable receivers 3704. Hinged flap 3705 may be lightly spring loadedso that it is normally in an upward position, but can be deflected bythe weight of a vial being dispensed. Hinged flap 3705 may serve toabsorb some of the energy of a falling vial, and prevent excessivejostling or bouncing of a vial in the dispense drawer. Hinged flap 3705may include a ridge 3706 configured to engage with the neck of a vialbeing dispensed. Ridge 3706 may reduce the tendency of a dispensed vialto rotate during dispensing.

FIG. 40 shows a rear orthogonal view of a lower portion of cassette3602, and illustrates the operation of a brake 4001. Brake 4001 includesgear teeth 4002. When cassette 3602 is installed in dispenser 3601, apart of dispenser 3601 (not shown) pushes rack 4004 upward, which turnsgear 4005, and draws brake 4001 downward, out of engagement with gear3801 so that cassette 3602 can operate to dispense vials or other items.Brake 4001 may be helpful, for example, during shipment or transport ofa full cassette, to prevent intentional or accidental removal of itemsfrom cassette 3602 by turning gears 3801.

Other measures may be taken to prevent accidental or intentionaldiversion of items from cassette 3602. For example, as shown in FIG. 41,openings 4101 may be provided in back 4102, side 4103, and top 4104 ofcassette 3602, to accommodate tamper-evident ties that also disable theoperation of cassette 3602. FIGS. 42 and 43 show cassette 3602 with ties4201 installed. Ties 4201 may be, for example, plastic “zip” ties or asimilar kind of tie, that is not conveniently removable without cuttingthe tie. Ties 4201 may be installed when cassette is filled, and notlegitimately removed until cassette 3602 is ready to be installed in adrawer such as drawer 106. If cassette 3602 arrives at its destinationwith all of ties 4201 intact, it may be assumed that no tampering oraccidental dispensing has occurred. If any of ties 4201 is missing ordamaged, diversion may be suspected. When a decision is made to installcassette 3602 in a dispenser or drawer, the restock technician can cutand remove ties 4201 before installation.

Other kinds of tamper-evident mechanisms may be used as well, instead ofor in addition to ties 4201.

Additional Dispenser for Syringes and Other Similarly-Shaped Items

FIGS. 44A and 44B illustrate upper and lower views of a dispensingmechanism 4400 in accordance with embodiments of the invention.Dispensing mechanism 4400 may be especially useful for dispensingcylindrical items such as syringes, although dispensing mechanism 4400may be useful for dispensing other similarly-shaped items as well.

Example dispensing mechanism 4400 comprises a dispenser 4401 and acassette 4402, which are separable. For example, dispenser 4401 andcassette 4402 may snap together, may be separable with the removal ofone or a small number of screws, or may be reasonably separable in someother way without damage to either dispenser 4401 or cassette 4402. Inthis way, restocking may be accomplished by replacing a depletedcassette 4402 with a full cassette 4402.

As is visible in FIG. 44B, a connector 4403, compatible with connectors302 on rails 201, is positioned to engage one of connectors 302 whendispensing mechanism 4400 is installed in restock drawer 106. Dispenser4401 defines an opening 4404 at the bottom of dispensing mechanism 203,through which items are dispensed. Dispensing mechanism 4400 may beremovably secured to one of rails 201 using a snap mechanism, one ormore screws, or by another method.

Preferably, cassette 4402 does not contain any active electricalcomponents. All of the active components of dispensing mechanism 4400reside in dispenser 4401. For example, an antenna 4405 can excite apassive memory chip 4406 in cassette 4402, to determine the contents ofcassette 4402 (written into passive memory chip 4406 when cassette 4402was filled at a remote location). If desired, antenna 4405 can also beused to update the data in passive memory chip 4406. This wireless dataexchange may use any suitable wireless protocol, for example Near FieldCommunications (NFC), radio frequency identification (RFID), or anotherwireless protocol.

Dispenser 4401 can preferably automatically detect the installation andremoval of cassette 4402. This automatic detection may facilitate theinventory and tracking of items, and also can help prevent illicitdiversion of items. The detection may be accomplished in any suitableway, for example periodic polling using antenna 4405, a contact sensor(not shown) that can detect the presence of cassette 4402electromechanically, or by another technique.

The main body of cassette 4402 may be made of a clear material, so thata user can see the contents of cassette 4402.

In other embodiments, a dispensing mechanism in accordance withembodiments of the invention may not have the separable architecture ofdispensing mechanism 4400, but may be a single unit including space forstoring items to be dispense and including an actuator and othercomponents for dispensing items. In other embodiments that do include acassette, the cassette may include active components, for example amotor or other actuator, light emitters for sensing, or othercomponents.

Although not shown in FIGS. 44A and 44B, a button and light similar tobutton 601 and light 602 discussed above, for communication between arestocking technician or other user and computer 103 of cabinet 100.

FIG. 45 shows an oblique view of dispenser 4401 with some parts removed,revealing internal details of the operation of dispenser 4401.

One or more light emitters and receivers 4501, 4502 may be positionednear the bottom of dispenser 4401. In operation, light from lightemitters may reflect from a reflective surface of dispenser 4401 (notvisible in FIG. 45) and return to the light receivers, so long as it isnot interrupted by an item being dispensed and falling through the“light curtain” formed across opening. When an item is dispensed throughopening 4404, it interrupts the light received by one or more of thelight receivers, and dispenser 4401 can note that an item has in factbeen dispensed. If no light interruption is detected despite a commandto dispense an item, computer 103 may assume that a misfeed or otherproblem has occurred, or that cassette 4402 is empty. By using moresophisticated monitoring strategies, accidental dispensing of multipleitems may be detected. For example, if two interruptions of the lightcurtain are detected closely spaced in time, a double feed may beindicated. The one or more light emitters may be of any suitable type ofemitter, and may emit light in any suitable wavelength or combinationsof wavelengths. For example, a light emitter in an embodiment of theinvention may be a light emitting diode, a laser such as a verticalcavity semiconductor emitting laser (VCSEL) or another kind of lightsource, and may emit visible light, infrared light, or light in othersuitable wavelength bands or combinations of wavelength bands. In otherembodiments, the surface may be non-reflective, for example black, andthe dispensing of an item may be detected by noting an increase in theintensity of light reaching receivers 4502, rather than a decrease, aslight is reflected from the item being dispensed.

In other embodiments, light emitters and receivers 4501, 4502 may be onopposite sides of opening 4404, so that receivers 4502 receive lightdirectly from light emitters 4501 until the light is interrupted by thedispensing of an item.

A cable (not visible) couples connector 4403 directly or indirectly witha circuit board 4503, to which a motor 4504 is connected. Motor 4504 maybe, for example, a stepper motor whose angular position can be readilymoved incrementally and held. In that case, an item may be dispensed byadvancing motor 4504 by one rotation. If the light curtain does notdetect that an item is dispensed, motor 4504 may be advanced further,and if no dispensing is yet detected, an error message may be generated,or it may be assumed that cassette 4402 is empty. Alternatively, motor4504 may be a simple DC or AC motor, in which case dispensing may beaccomplished by simply running motor 4504 until the dispensing of anitem is detected, and then shutting off the motor. A time limit may beimposed, such that if no dispensing is detected within the time limitwith motor 4504 running, the motor may be shut off and an error messagegenerated.

Motor 4504 turns a cam 4505 in the direction shown, the function ofwhich is explained in more detail below.

A microprocessor, microcontroller, or similar controlling circuitry mayreside within dispenser 4401, and may operate the various activecomponents and sensors of dispenser 4401 in response to high-levelcommands from a supervisory controller elsewhere within restock drawer106, or from computer 103. In that case, dispenser 4401 is considered a“smart” dispenser, because it includes some processing intelligence.However, other architectures are possible. For example, logic signalsfrom a supervisory controller elsewhere within restock drawer 106 mayoperate dispenser 4401.

FIG. 46 illustrates a cutaway oblique view of cassette 4402, and alsocam 4505 (which is part of dispenser 4401 rather than cassette 4402).Cassette 4402 is formed by two side pieces 4601 and 4602, whichcooperate to define a serpentine channel 4603 between them. A number ofsyringes 2000 are disposed in serpentine channel 4603, and feed towardthe bottom of cassette 4402 as syringes are dispensed. While otherdimensions are possible, example cassette 4402 is about 234 mm high, 71mm deep, and 153 mm wide, and thus displaces an overall volume of lessthan 2600 cubic centimeters, and can hold up to 50 or more syringes2000. Cassette 4402 thus displaces about 52 cubic centimeters for eachsyringe that can be stored in cassette 4402. While syringes 2000 havinga 2 ml capacity are shown, cassette 4402 may be configured to dispensesyringes having a smaller overall length by placing a spacer (not shown)within cassette 4402. In various embodiments, cassette 4402 may displaceless than 50, less than 40, less than 30, or less than 25 cubiccentimeters for each item stored in cassette 4402 at full capacity.

FIGS. 47A-47C show orthogonal section views of the lower part ofcassette 4402, as well as cam 4505, and their operation to dispense asyringe 2000. A bottom 4701 of cassette 4402 defines an opening 4702 anda ledge 4703. A movable slide 4704 defines a slot in which syringe 2000a is positioned in FIG. 22A. Slide 4704 is biased to the left by spring4705, such that syringe 2000 a remains suspended by ledge 4703. Syringe2000 a is in position to be dispensed, while cassette 4402 containsadditional syringes such as syringe 2000 b. Spring 4705 also ensuresthat the syringes in cassette 4402 are not accidentally dispensed whencassette 4402 is separated from dispenser 4401, for example duringtransport from a central pharmacy to cabinet 100.

When it is desired to dispense a syringe, motor 4504 (not shown in FIGS.47A-47C) turns cam 4505 as shown in FIG. 47B. Cam 4505 acts againstsurface 4706 of slide 4704, moving slide 4704 to the right, aligning theslot in slide 4704 with opening 4702 in bottom 4701 of cassette 4402.Syringe 2000 a can accordingly drop through opening 4702 and intodispense drawer 107.

In FIG. 47C, cam 4505 has rotated past its contact with slide 4704,allowing spring 4705 to force slide 4704 back to its nominal position.Sensor electronics may sense the dispensing of syringe 2000 a, or thatslide 4704 is back to its nominal position, and may shut off motor 4504,stopping cam 4505. Syringe 2000 b drops into the slot in slide 4704,resting on ledge 4703, in preparation for its future dispensing.

In other embodiments, an actuator other than a motor may be used. Forexample, a solenoid or memory metal actuator may provide a translationalmotion that is used to directly translate slide 4704 against spring4705. Other kinds of actuators and driving arrangements are possible.

In some embodiments, dispensing mechanism 4400 may include one or moresensors for directly detecting movement of a mechanical component ofdispensing mechanism 4400. For example, slide 4704 may be generallynon-reflective, but may include a reflective sticker placed fordetection by a reflective optical when slide 4704 moves under the actionof cam 4505. The passing of the reflective sticker, as detected by thesensor, verifies that slide 4704 has actually moved. A similar effectmay be achieved by placing a magnet on slide 4704 and detecting itspassing of a Hall Effect sensor. Similarly, the movement of cam 4505could be directly sensed. A processor or other circuitry withindispenser 4401 can interpret a signal produced by the sensor to verifythe motion of the slide or cam. This direct measurement providesadditional feedback as to the operation of dispensing mechanism 4400.For example, if it is verified using the additional sensor that slide4704 has moved sufficiently far that an item should be dispensed, butthe light curtain sensor does not detect the dispensing of an item, itmay be determined that cassette 4402 is empty, or it may be suspectedthat an error has occurred.

FIG. 48 shows a cutaway oblique view of a portion of cassette 4402, andillustrates the operation of a brake 4801. Brake 4801 includes a hookedlever 4802. When cassette 4402 is disengaged from dispenser 4401, hookedlever 4802 is biased downward by spring 4803, so that hooked lever 4802hooks into opening 4804, preventing motion of slide 4704. When cassette4402 is engaged with dispenser 4401, a feature of dispenser 4401 (forexample pin 4407 visible in FIG. 44A) pushes hooked lever 4802 into theupward position shown, so that slide 4704 can move freely. Brake 4801may be helpful, for example, during shipment or transport of a fullcassette, to prevent intentional or accidental removal of items fromcassette 4402 by moving slide 4704.

Other measures may be taken to prevent accidental or intentionaldiversion of items from cassette 4402. For example, as shown in FIGS.49A and 49B, which are upper and lower oblique views of cassette 4402,openings 4901 may be provided in top 4902, side 4903, and bottom 4904 ofcassette 4402, to accommodate tamper-evident ties that also disable theoperation of cassette 4402. FIGS. 50 and 51 show cassette 4402 with ties5001 installed. Ties 5001 may be, for example, plastic “zip” ties or asimilar kind of tie, that is not conveniently removable without cuttingthe tie. Ties 5001 may be installed when cassette is filled, and notlegitimately removed until cassette 4402 is ready to be installed in adrawer such as drawer 106. If cassette 4402 arrives at its destinationwith all of ties 5001 intact, it may be assumed that no tampering oraccidental dispensing has occurred. If any of ties 5001 is missing ordamaged, diversion may be suspected. When a decision is made to installcassette 5502 in a dispenser or drawer, the restock technician can cutand remove ties 5001 before installation.

Other kinds of tamper-evident mechanisms may be used as well, instead ofor in addition to ties 5001.

Light Detection

In each of the embodiments described above, one or more light emittersand detectors are used to create a “light curtain” at the bottom of eachdispenser, for detecting items being dispensed, or that an item may nothave been dispensed when desired. Additional details of exampleimplementations and uses for the light emitters and detectors are givenbelow.

FIG. 52 schematically illustrates an arrangement of a light curtain,using only one emitter and one detector for simplicity of explanation. Alight emitter 5201 emits light through space 5202 toward a surface 5203.Light emitter 5201 may be, for example, an infrared light emitting diode(LED) emitting light at a wavelength of about 940 nm, or may be anotherkind of light emitter. In some embodiments, emitter 5201 may be an SFH4641 infrared LED emitter available from Osram Sylvania having officesin Wilmington, Mass., USA.

Surface 5203 may be reflective, for example a mirrored or diffuse whitesurface, so that some of the light reflected from surface 5203 isdirected to a sensor 5204. Sensor 5204 may be, for example, a modelVEMT3700F phototransistor available from Vishay Intertechnology ofMalvern, Pa., USA. Sensor 5204 produces a signal indicating theintensity of light falling on it. In the configuration of FIG. 52, thetravel of light from emitter 5201 to surface 5203 and back to sensor5204 is unobstructed, so that sensor 5204 will produce a signalindicating that it is receiving light.

When an item is dispensed through space 5202, the light is interrupted,as shown in FIG. 53. For example, vial 5301 interrupts the lightemanating from emitter 5201 so that it does not reach surface 5203, anddoes not reflect to sensor 5204. Some light may scatter from the surfaceof vial 5301, but little will reach sensor 5204, and the signal producedby sensor 5204 in this state indicates that little or no light isreaching sensor 5204. In this arrangement, the dispensing of an item isindicated by a decrease in the light detected by sensor 5204.

In other embodiments, surface 5203 may be non-reflective, for exampleblack. This arrangement may be especially useful when the items to bedispensed are themselves highly reflective. For example, FIG. 54 shows alight curtain having a black surface 5401, with no item being dispensed.Surface 5401 substantially absorbs the light hitting it from emitter5201, and this sensor 5204 will produce a signal indicating that it isreceiving little or no light.

FIG. 55 illustrates the dispensing of an item between emitter 5201 andnon-reflective surface 5401. In this example, a syringe 5501 isreflective, and scatters light toward sensor 5204, so that sensor 5204will produce a signal indicating that it is receiving light when syringe5501 passes through space 5202. In this arrangement, the dispensing ofan item is indicated by an increase in the light detected by sensor5204.

In other embodiments, a “transmissive” light curtain may be used, thatdoes not rely on the reflection of light for detecting dispensed items.For example, FIG. 56 shows an emitter 5201 and a receiver 5601 on anopposite side 5602 of space 5202 from emitter 5201. Receiver 5601receives light directly from emitter 5201.

FIG. 57 illustrates the dispensing of an item between emitter 5201 andreceiver 5601. In this example, a blister pack 5701 interrupts the lightemanating from emitter 5201 so that it does not reach receiver 5601. Inthis arrangement, the dispensing of an item is indicated by a decreasein the light detected by sensor 5601.

In other embodiments, a combination of these techniques may be used. Forexample, a sensor may be monitored to detect both increases anddecreases in received light.

FIGS. 58-60 show schematic diagrams of circuitry for an example systemhaving three light emitters and six light receivers. As shown in FIG.58, three emitters 5801 can be turned on or off, for example by acontroller within cabinet 100 or within a specific dispenser, usinginput 5802.

As shown in FIG. 59, six light receivers in the form of phototransistors5901 produce outputs 5902 a-5902 f indicating the intensity of lightbeing received by the respective phototransistors 5901. In this example,each output is a voltage.

FIG. 60 illustrates the generation of a detection signal from theoutputs 5902 a-c of three of phototransistors 5901. Output 5902 a is fedto a comparator 6001 a, which compares the voltage of output 5902 a witha first reference voltage 6002 a. If output 5902 a exceeds referencevoltage 6002 a, then output 6003 a goes to a digital “high” value, butis otherwise low.

Similarly, comparator 6001 c compares the voltage of output 5902 c witha reference voltage 6002 c, and produces output 6003 c.

Output 5902 b is fed to two comparators 6001 b and 6001 d. Comparator6001 b operates similarly to comparators 6001 a and 6001 c, producing a“high” output at output 5903 b when the voltage of sensor output 5902 bexceeds reference value 6002 b. However, comparator 6001 d operates inthe opposite sense, comparing sensor output voltage 5902 b with a highreference 6002 d. Output 6003 d is “high” when output 5902 b is belowreference voltage 6002 d, but is otherwise low.

All of outputs 6003 a-d are fed to a quad-input AND gate 6004, whichproduces a “high” detection signal 6005 only when all four of the inputsare high. That is, detection signal 6005 is high only when outputs 5902a-c exceed references 6002 a-c, and output 5902 b is below reference6002 d. With regard to comparators 6001 c, this corresponds to thesituation shown in FIG. 52, where three receivers are receiving lightsufficient to exceed a threshold. With regard to the fourth comparator6001 d, reference 6002 d may be set high enough that receiver output5902 b normally does not exceed it, but low enough to possibly “see”glinting reflections. The use of two different comparator senses issometimes called “window” detection.

Detection output 6005 will normally be high, but will go low when anyone or any number of comparators 6001 a-d gives a low signal. Output6005 may generate an interrupt in a processor coupled to the appropriatedispensing mechanism to signal the dispensing of an item. In otherembodiments, detection signal 6005 may be polled.

The controller may watch for the detection signal immediately aftercommanding that an item be dispensed, to confirm proper dispensing or todetect a failure to dispense an item.

However, the controller may monitor detection signal 6005 at other timesas well, to detect a detection signal not produced in conjunction withthe dispensing of an item. If detection signal 6005 goes low at such atime, it may be suspected that a diversion attempt is underway, with afinger or tool being inserted into the dispensing mechanism from below.A warning signal may be generated to indicate the suspected diversion ortampering.

Receiver outputs 5902 d-f may be processed in a similar way, to providea second detection signal. Any workable number of emitters and receiversmay be used, with any number triggering on a decrease of light reachingthe respective receiver or triggering on an increase of light reachingthe respective receiver.

For example, in a system similar to the system of FIGS. 54 and 55, usinga black surface 5401 and relying on reflection from an item beingdispensed for detection, most or all of the receivers may be configuredto generate a detection signal upon an increase of light being received.

Any or all of the reference voltages may be settable by a controller,for calibration purposes. For example, each of the reference voltagesmay be the output of a respective digitally-controlled potentiometer.The references may be re-calibrated for each dispense request, forexample by turning on emitters 5801 and adjusting the reference voltagesto find the tripping point for each comparator 6001. Once the trippingpoint is found, the reference voltage may be re-adjusted to a percentageof the tripping voltage. Preferably, each reference is calibratedindividually.

In the claims appended hereto, the term “a” or “an” is intended to mean“one or more.” The term “comprise” and variations thereof such as“comprises” and “comprising,” when preceding the recitation of a step oran element, are intended to mean that the addition of further steps orelements is optional and not excluded. It is to be understood that anyworkable combination of the elements and features disclosed herein isalso considered to be disclosed.

The invention has now been described in detail for the purposes ofclarity and understanding. However, those skilled in the art willappreciate that certain changes and modifications may be practicedwithin the scope of the appended claims.

What is claimed is:
 1. A dispensing mechanism, comprising: a dispenser;a cassette that stores a supply of items to be dispensed; a connectorfor receiving electrical signals from a cabinet in which the dispensingmechanism is installed, wherein the connecter enables the dispensingmechanism to be removably electrically connected to the cabinet; anactuator that moves in response to the electrical signals; a housing inthe cassette for storing the items to be dispensed, the housing definingan opening at a bottom of the housing, wherein items are to be dispensedthrough the opening, and wherein the housing is configured such thatitems feed by gravity toward the opening as items are dispensed; amoveable slide driven by the actuator, the moveable slide having a slotthrough the movable slide, wherein items to be dispensed fall one at atime into the slot; and a spring that biases the slide into a defaultposition in which the slot of the moveable slide is not aligned with theopening; wherein when the slide is moved by the actuator, the slidetranslates against the action of the spring into a position in which theslot in the slide aligns with the opening, allowing a single item in theslot to fall through the opening to be dispensed; wherein the connectorand the actuator are comprised in the dispenser, and the slide and thespring are comprised in the cassette; wherein the dispenser and thecassette are separable; and wherein the cassette does not include anyactive electrical components.
 2. The dispensing mechanism of claim 1,wherein the actuator is selected from the group consisting of a motor, asolenoid, and a memory metal.
 3. The dispensing mechanism of claim 1,wherein the items in the housing are visible from outside the housingthrough a wall of the housing.
 4. The dispensing mechanism of claim 1,further comprising: one or more light emitters positioned to form alight curtain below the opening; and one or more receivers that detectlight from the one or more light emitters, the one or more lightemitters and the one or more receivers positioned such that the lightemitted by at least one of the one or more light emitters is interruptedby the passage of a dispensed item through the opening.
 5. Thedispensing mechanism of claim 4, wherein the one or more receiversdetect light reflected from a far wall of the opening or from an itembeing dispensed.
 6. The dispensing mechanism of claim 4, wherein the oneor more receivers detect light received directly from one or more of theone or more light emitters.
 7. The dispensing mechanism of claim 1,wherein: the cassette includes a wirelessly-readable memory; and thedispenser includes a reader for reading the wirelessly-readable memory.8. The dispensing mechanism of claim 1, wherein the dispenser ismechanically removably securable to the cabinet.
 9. A dispensingmechanism, comprising: a dispenser; and a cassette that stores a supplyof items to be dispensed; a connector for receiving electrical signalsfrom a cabinet in which the dispensing mechanism is installed, whereinthe connecter enables the dispensing mechanism to be removablyelectrically connected to the cabinet; an actuator that moves inresponse to the electrical signals; a housing in the cassette forstoring the items to be dispensed, the housing defining an opening at abottom of the housing, wherein items are to be dispensed through theopening, and wherein the housing is configured such that items feed bygravity toward the opening as items are dispensed; a moveable slidedriven by the actuator, the moveable slide having a slot through themovable slide, wherein items to be dispensed fall one at a time into theslot; and a spring that biases the slide into a default position inwhich the slot of the moveable slide is not aligned with the opening;wherein: the connector and the actuator are comprised in the dispenser,and the slide and the spring are comprised in the cassette; thedispenser and the cassette are separable; the cassette does not includeany active electrical components; when the slide is moved by theactuator, the slide translates against the action of the spring into aposition in which the slot in the slide aligns with the opening,allowing a single item in the slot to fall through the opening to bedispensed; and the cassette further comprises a brake that isautomatically engaged when the cassette is removed from the dispenser,the brake hindering movement of the slide when the brake is engaged. 10.The dispensing mechanism of claim 9, wherein the dispenser ismechanically removably securable to the cabinet.
 11. A dispensingmechanism, comprising: a dispenser; and a cassette that stores a supplyof items to be dispensed; a connector for receiving electrical signalsfrom a cabinet in which the dispensing mechanism is installed, whereinthe connecter enables the dispensing mechanism to be removablyelectrically connected to the cabinet; an actuator that moves inresponse to the electrical signals; a housing in the cassette forstoring the items to be dispensed, the housing defining an opening at abottom of the housing, wherein items are to be dispensed through theopening, and wherein the housing is configured such that items feed bygravity toward the opening as items are dispensed; a moveable slidedriven by the actuator, the moveable slide having a slot through themovable slide, wherein items to be dispensed fall one at a time into theslot; and a spring that biases the slide into a default position inwhich the slot of the moveable slide is not aligned with the opening;wherein when the slide is moved by the actuator, the slide translatesagainst the action of the spring into a position in which the slot inthe slide aligns with the opening, allowing a single item in the slot tofall through the opening to be dispensed; wherein the connector and theactuator are comprised in the dispenser, and the slide and the springare comprised in the cassette; wherein the dispenser and the cassetteare separable; wherein the cassette does not include any activeelectrical components; and wherein the housing defines a serpentinechannel through which items feed by gravity toward the opening.
 12. Thedispensing mechanism of claim 11, wherein the dispenser is mechanicallyremovably securable to the cabinet.